90 vette ecm issues
Thread Starter
3rd Gear
Joined: Aug 2025
Posts: 3
Likes: 0
90 vette ecm issues
Kinda long winded here but need help
car running fine installed new radiator, idleing getting to temp started rough idle then shut down, dumping excessive fuel in all 8 cylinders narrowed it down to ECM, orderd rebuilt one pre-programmed (with memcal) received it wouldn't start had to use old memcal, started up but 1st I noticed primary fan cam on instantly (cold car) , few days later speedo stopped working but works on and off but when it wants to but when the speedo dont work neither does the air conditioner, speedo start working so does the air conditioner.
Can't figure it out!! Anyone had this??
car running fine installed new radiator, idleing getting to temp started rough idle then shut down, dumping excessive fuel in all 8 cylinders narrowed it down to ECM, orderd rebuilt one pre-programmed (with memcal) received it wouldn't start had to use old memcal, started up but 1st I noticed primary fan cam on instantly (cold car) , few days later speedo stopped working but works on and off but when it wants to but when the speedo dont work neither does the air conditioner, speedo start working so does the air conditioner.
Can't figure it out!! Anyone had this??
IB Staff
Joined: Feb 2009
Posts: 10,564
Likes: 4
Kinda long winded here but need help
car running fine installed new radiator, idleing getting to temp started rough idle then shut down, dumping excessive fuel in all 8 cylinders narrowed it down to ECM, orderd rebuilt one pre-programmed (with memcal) received it wouldn't start had to use old memcal, started up but 1st I noticed primary fan cam on instantly (cold car) , few days later speedo stopped working but works on and off but when it wants to but when the speedo dont work neither does the air conditioner, speedo start working so does the air conditioner.
Can't figure it out!! Anyone had this??
car running fine installed new radiator, idleing getting to temp started rough idle then shut down, dumping excessive fuel in all 8 cylinders narrowed it down to ECM, orderd rebuilt one pre-programmed (with memcal) received it wouldn't start had to use old memcal, started up but 1st I noticed primary fan cam on instantly (cold car) , few days later speedo stopped working but works on and off but when it wants to but when the speedo dont work neither does the air conditioner, speedo start working so does the air conditioner.
Can't figure it out!! Anyone had this??
Instead, please find the correct section, based on the generation of the Corvette.
Go back to the main forum page:
https://www.corvetteforum.com/forums/
Now start to slowly scroll down until you see the generation of your Corvette. C4 Corvettes, 1984 - 1996:
https://www.corvetteforum.com/forums...-1984-1996-19/
Got a technical question about the C4 Corvette? Use the C4 Tech section:
https://www.corvetteforum.com/forums...-1984-1996-19/
We encourage new members to take some time to browse around the site and read the Announcements and Stickies as they contain important and frequently asked information.
Thank-you
